Public health management of hepatitis B virus contacts

To the Editor: The Auckland Statement on Viral Hepatitis, released in September 2012, called for action to prevent new hepatitis B and C infections.1 Estimates suggest that more than 200 000 Australians are living with chronic hepatitis B virus (HBV) infection, with nearly half being unaware of their diagnosis.2,3 Childhood vaccination is crucial to HBV prevention, but many people from high-risk populations, including immigrants and refugees from endemic countries, are infected before arriving in Australia.4 Targeted screening of high-risk groups for susceptibility or undiagnosed infection is therefore also integral to public health management of HBV infection.

Although susceptible household contacts and sexual partners of all patients with HBV infection are at risk, most jurisdictions only follow up contacts for notifications of acute HBV infection and not unspecified or chronic infections, which represent over 95% of notifications.5 Contact testing therefore relies on local doctors, but contacts often do not attend the same clinic as the index patient, and incomplete contact follow-up is inevitable. Overseas data suggest that only 25% of contacts of patients with HBV are immune.6 A Victorian study found that 68% of adult household contacts were screened, but only 31% were fully vaccinated, and half the surveyed doctors were unaware of the availability of state-funded HBV vaccine for this indication.3

In 2011, a project was initiated to determine how frequently contacts of patients with chronic HBV infection seen at a tertiary referral hospital in Victoria had been tested and/or vaccinated. Ethics approval for the project was obtained from Melbourne Health. Dedicated funding was available for exploring knowledge of HBV transmission among patients with HBV, assessing their contacts’ HBV status, and determining the proportion of contacts willing to accept serological testing and free vaccination. Consent forms were delivered to contacts by the index patients. However, the study was prematurely terminated because of poor contact response rates, suggesting tertiary care-based contact tracing is unlikely to be effective.

Instead of the current haphazard approach to HBV contact management, improved education and support for patients and general practitioners is needed. Active follow-up by health departments of all notifications would also be ideal. If this is not feasible, a systematic approach to support contact tracing in the primary care setting might have merit, but remains unproven. Missed opportunities to diagnose infection or vaccinate susceptible contacts are public health failures.